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    <title>topic Profiler shows code spends a lot of time in thread library in Intel® oneAPI Math Kernel Library</title>
    <link>https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/Profiler-shows-code-spends-a-lot-of-time-in-thread-library/m-p/832067#M5707</link>
    <description>Running against libiompprof5.so should at least tell you if these OpenMP function times are associated with thread work imbalance or the like. It should also help you find out if there is a favorable effect from setting appropriate KMP_AFFINITY values. Work imbalance, for example, could arise from certain pairs of threads on different CPUs working on the same or adjacent cache lines, thus taking longer, while other threads complete quickly.&lt;BR /&gt;Note that bare-bones use of libiompprof5 simply writes a useful text summary in guide.gvs in your working directory.</description>
    <pubDate>Thu, 28 Apr 2011 19:56:10 GMT</pubDate>
    <dc:creator>TimP</dc:creator>
    <dc:date>2011-04-28T19:56:10Z</dc:date>
    <item>
      <title>Profiler shows code spends a lot of time in thread library</title>
      <link>https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/Profiler-shows-code-spends-a-lot-of-time-in-thread-library/m-p/832066#M5706</link>
      <description>Hi,&lt;BR /&gt;&lt;BR /&gt;&lt;P&gt;We are trying to profile an in-house developed code and we
noticed that at the top of the list, taking up 20% of the time, is a function
called kmp_hyper_barrier_release. We are not compiling our code with OpenMP
specifically, but we are using Pardiso in the MKL library which I believe does use OpenMP.
The puzzling thing is that it seems that the code is only spending a fraction
of the time inside the MKL library (~15%), so it is strange that this kmp
function is taking up so much time. Even worse, there are two more kmp functions:
kmp_x86_pause (taking up 11%), and kmp_execute_tasks (6%). I was wondering if
anybody could explain what these functions do and why they are impacting the
performance of our code so dramatically.&lt;/P&gt;

&lt;P&gt;&lt;/P&gt;

&lt;P&gt;Thanks,&lt;/P&gt;Dave</description>
      <pubDate>Thu, 28 Apr 2011 17:27:34 GMT</pubDate>
      <guid>https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/Profiler-shows-code-spends-a-lot-of-time-in-thread-library/m-p/832066#M5706</guid>
      <dc:creator>Rawlins__David</dc:creator>
      <dc:date>2011-04-28T17:27:34Z</dc:date>
    </item>
    <item>
      <title>Profiler shows code spends a lot of time in thread library</title>
      <link>https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/Profiler-shows-code-spends-a-lot-of-time-in-thread-library/m-p/832067#M5707</link>
      <description>Running against libiompprof5.so should at least tell you if these OpenMP function times are associated with thread work imbalance or the like. It should also help you find out if there is a favorable effect from setting appropriate KMP_AFFINITY values. Work imbalance, for example, could arise from certain pairs of threads on different CPUs working on the same or adjacent cache lines, thus taking longer, while other threads complete quickly.&lt;BR /&gt;Note that bare-bones use of libiompprof5 simply writes a useful text summary in guide.gvs in your working directory.</description>
      <pubDate>Thu, 28 Apr 2011 19:56:10 GMT</pubDate>
      <guid>https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/Profiler-shows-code-spends-a-lot-of-time-in-thread-library/m-p/832067#M5707</guid>
      <dc:creator>TimP</dc:creator>
      <dc:date>2011-04-28T19:56:10Z</dc:date>
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